.TH std::forward_list 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::forward_list \- std::forward_list

.SH Synopsis
   Defined in header <forward_list>
   template<

       class T,                                                       \fB(1)\fP \fI(since C++11)\fP
       class Allocator = std::allocator<T>

   > class forward_list;
   namespace pmr {

       template< class T >
       using forward_list = std::forward_list<T,                      \fB(2)\fP \fI(since C++17)\fP
   std::pmr::polymorphic_allocator<T>>;

   }

   std::forward_list is a container that supports fast insertion and removal of
   elements from anywhere in the container. Fast random access is not supported. It is
   implemented as a singly-linked list. Compared to std::list this container provides
   more space efficient storage when bidirectional iteration is not needed.

   Adding, removing and moving the elements within the list, or across several lists,
   does not invalidate the iterators currently referring to other elements in the list.
   However, an iterator or reference referring to an element is invalidated when the
   corresponding element is removed (via erase_after) from the list.

   std::forward_list meets the requirements of Container (except for the size member
   function and that operator=='s complexity is always linear), AllocatorAwareContainer
   and SequenceContainer.

.SH Template parameters

               The type of the elements.

               The requirements that are imposed on the elements depend on the
               actual operations performed on the container. Generally, it is     (until
               required that element type is a complete type and meets the        C++17)
               requirements of Erasable, but many member functions impose
               stricter requirements.
               The requirements that are imposed on the elements depend on the
               actual operations performed on the container. Generally, it is
               required that element type meets the requirements of Erasable, but
   T         - many member functions impose stricter requirements. This container
               (but not its members) can be instantiated with an incomplete
               element type if the allocator satisfies the allocator completeness (since
               requirements.                                                      C++17)

                         Feature-test macro             Value    Std    Feature
                                                                       Minimal
               __cpp_lib_incomplete_container_elements 201505L \fI(C++17)\fP incomplete
                                                                       type
                                                                       support


               An allocator that is used to acquire/release memory and to
               construct/destroy the elements in that memory. The type must meet the
               requirements of Allocator.
   Allocator - The behavior is undefined
               \fI(until C++20)\fP
               The program is ill-formed
               \fI(since C++20)\fP if Allocator::value_type is not the same as T.

.SH Member types

   Member type     Definition
   value_type      T
   allocator_type  Allocator
   size_type       Unsigned integer type (usually std::size_t)
   difference_type Signed integer type (usually std::ptrdiff_t)
   reference       value_type&
   const_reference const value_type&
   pointer         std::allocator_traits<Allocator>::pointer
   const_pointer   std::allocator_traits<Allocator>::const_pointer
   iterator        LegacyForwardIterator to value_type
   const_iterator  LegacyForwardIterator to const value_type

.SH Member functions

   constructor        constructs the forward_list
                      \fI(public member function)\fP
   destructor         destructs the forward_list
                      \fI(public member function)\fP
   operator=          assigns values to the container
                      \fI(public member function)\fP
   assign             assigns values to the container
                      \fI(public member function)\fP
   assign_range       assigns a range of values to the container
   (C++23)            \fI(public member function)\fP
   get_allocator      returns the associated allocator
                      \fI(public member function)\fP
.SH Element access
   front              access the first element
                      \fI(public member function)\fP
.SH Iterators
   before_begin       returns an iterator to the element before beginning
   cbefore_begin      \fI(public member function)\fP
   begin              returns an iterator to the beginning
   cbegin             \fI(public member function)\fP
   end                returns an iterator to the end
   cend               \fI(public member function)\fP
.SH Capacity
   empty              checks whether the container is empty
                      \fI(public member function)\fP
   max_size           returns the maximum possible number of elements
                      \fI(public member function)\fP
.SH Modifiers
   clear              clears the contents
                      \fI(public member function)\fP
   insert_after       inserts elements after an element
                      \fI(public member function)\fP
   emplace_after      constructs elements in-place after an element
                      \fI(public member function)\fP
   insert_range_after inserts a range of elements after an element
   (C++23)            \fI(public member function)\fP
   erase_after        erases an element after an element
                      \fI(public member function)\fP
   push_front         inserts an element to the beginning
                      \fI(public member function)\fP
   emplace_front      constructs an element in-place at the beginning
                      \fI(public member function)\fP
   prepend_range      adds a range of elements to the beginning
   (C++23)            \fI(public member function)\fP
   pop_front          removes the first element
                      \fI(public member function)\fP
   resize             changes the number of elements stored
                      \fI(public member function)\fP
   swap               swaps the contents
                      \fI(public member function)\fP
.SH Operations
   merge              merges two sorted lists
                      \fI(public member function)\fP
   splice_after       moves elements from another forward_list
                      \fI(public member function)\fP
   remove             removes elements satisfying specific criteria
   remove_if          \fI(public member function)\fP
   reverse            reverses the order of the elements
                      \fI(public member function)\fP
   unique             removes consecutive duplicate elements
                      \fI(public member function)\fP
   sort               sorts the elements
                      \fI(public member function)\fP

.SH Non-member functions

   operator==
   operator!=
   operator<
   operator<=
   operator>
   operator>=                   lexicographically compares the values of two
   operator<=>                  forward_lists
   \fI(C++11)\fP                      \fI(function template)\fP
   \fI(C++11)\fP(removed in C++20)
   \fI(C++11)\fP(removed in C++20)
   \fI(C++11)\fP(removed in C++20)
   \fI(C++11)\fP(removed in C++20)
   \fI(C++11)\fP(removed in C++20)
   (C++20)
   std::swap(std::forward_list) specializes the std::swap algorithm
   \fI(C++11)\fP                      \fI(function template)\fP
   erase(std::forward_list)     erases all elements satisfying specific criteria
   erase_if(std::forward_list)  \fI(function template)\fP
   (C++20)

     Deduction guides \fI(since C++17)\fP

.SH Notes

       Feature-test macro       Value    Std                   Feature
   __cpp_lib_containers_ranges 202202L (C++23) Ranges construction and insertion for
                                               containers

.SH Example

    This section is incomplete
    Reason: no example

.SH Category:
     * Todo no example
